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Determination of depositional environment and luminescence dating of Pleistocene deposits in the Biely Váh valley, southern foothills of the Tatra Mountains, Slovakia

Bejarano Arias, Ingrid LU (2020) In Dissertations in Geology at Lund University GEOR02 20192
Department of Geology
Abstract
The Tatra Mountains have had several glaciations during the Quaternary. The deposits located in the southern foothills were classified as glacifluvial, based on geomorphology, but its sediments have not been studied in detail. Therefore, this project focused on establishing the depositional history, processes, and age of the deposits in a gravel pit, located in the Biely Váh valley in these foothills. The combination of luminescence dating with sedimentological analysis, including clast shape and maximum particle size, were the methods of choice. For the luminescence dating eleven samples were collected from the units composed mainly of sand.
Initially optically stimulated luminescence (OSL) dating was used, but after applying the... (More)
The Tatra Mountains have had several glaciations during the Quaternary. The deposits located in the southern foothills were classified as glacifluvial, based on geomorphology, but its sediments have not been studied in detail. Therefore, this project focused on establishing the depositional history, processes, and age of the deposits in a gravel pit, located in the Biely Váh valley in these foothills. The combination of luminescence dating with sedimentological analysis, including clast shape and maximum particle size, were the methods of choice. For the luminescence dating eleven samples were collected from the units composed mainly of sand.
Initially optically stimulated luminescence (OSL) dating was used, but after applying the standard Single Aliquot Regeneration (SAR) protocol quality tests, it was evident that the quartz was poorly behaved with low signal intensity. The dose estimation gave bad results, even after attempting pulsed OSL and differential OSL. Therefore, it was decided to move on to feldspar grains. Given that there is a risk of fading and the fact that feldspar grains take longer to bleach, the corrective measurements were done by calculating the g-value and use of IR50 and pIRIR225 signals for the bleaching.
The sedimentological description yielded 13 units from the lower and upper outcrops in the study area. The results of the sedimentological analysis indicated that the process of deposition had a high energy component, representative of subaerial flows. Given the features of the sediments it was identified as a hyperconcentrated flow. Moreover, for the age determination the most likely water content of the sediments was chosen, the g-values and the equivalent dose were determined, using both IR50 and pIRIR225 signals. Subsequently, four ages were obtained per sample, one for each signal, and with and without correction for fading. From these, the uncorrected pIRIR225 ages were selected, since this signal has a lower fading rate which is supported by the obtained g-values, which were smaller than 1-1.5%.
The results were compared to the known glacial history of the Tatra Mountains. The obtained luminescence ages, which range from ca 200 to 260 ka, would correspond to the Riss glaciation. Both ages and sediment characteristics match those of the other deposits from the northern and southern Tatra foothills that also have been correlated to the Riss glaciation. Taken together, these results suggest a glacial advance to the present-day foothills of the High Tatras during the Riss glaciation and extensive deposition of glacifluvial sediments outside the ice margin. (Less)
Abstract (Swedish)
Tatrabergen, som ligger i västra delen av Karpaterna, har upplevt flera nedisningar under kvartärtiden. Avsättningarna i sluttningarna längs bergens södra sida har klassificerats som glacifluviala, baserat på geomorfologi, men har inte undersökts i detalj tidigare. Det här projektet fokuserar därför på att etablera avsättningshistoria och -processer samt avlagringarnas ålder i ett grustag i Biely Váh-dalen som skär genom dessa sluttningar. En kombination av luminiscensdatering och sedimentologisk analys, inklusive partikelform och maxpartikelstorlek (MPS), har använts. Elva prover från sandiga enheter samlades in för luminiscensdatering. Partikelanalys genomfördes i de grövre enheterna som innehöll sten och block.
Till en början användes... (More)
Tatrabergen, som ligger i västra delen av Karpaterna, har upplevt flera nedisningar under kvartärtiden. Avsättningarna i sluttningarna längs bergens södra sida har klassificerats som glacifluviala, baserat på geomorfologi, men har inte undersökts i detalj tidigare. Det här projektet fokuserar därför på att etablera avsättningshistoria och -processer samt avlagringarnas ålder i ett grustag i Biely Váh-dalen som skär genom dessa sluttningar. En kombination av luminiscensdatering och sedimentologisk analys, inklusive partikelform och maxpartikelstorlek (MPS), har använts. Elva prover från sandiga enheter samlades in för luminiscensdatering. Partikelanalys genomfördes i de grövre enheterna som innehöll sten och block.
Till en början användes optiskt stimulerad luminiscensdatering (OSL), men efter att ha tillämpat de kvalitetstester som ingår i ett standard Single Aliquot Regeneration (SAR) protokoll stod det klart att kvartsen hade dåliga luminiscensegenskaper med låg signalintensitet. Dosmätningarna gav dåliga resultat, även med pulserad OSL och differentiell OSL. Det blev därför bestämt att fortsätta mätningarna på fältspat istället. Eftersom det finns risk för s.k. fading och eftersom fältspatkorn tar längre tid på sig att nollställas, korrigerades resultaten med hjälp av uppmätta g-värden och nollställningen utvärderades genom att se på signalerna från både IR50 and pIRIR225.
Genom den sedimentologiska beskrivningen identifierades tretton enheter från den nedre och övre skärningen i undersökningsområdet. Resultaten av de sedimentologiska analyserna visade att avsättningen skedde i en miljö med hög energi genom subaerila sediment-vattenströmmar, utifrån sedimentegenskaperna klassificerade som hyperkoncentrerade strömmar. För åldersberäkningen bestämdes den sannolika vattenkvoten hos sedimenten, och g-värden och ekvivalent dos bestämdes för både IR50 and pIRIR225 signalerna. Därefter beräknades fyra åldrar per prov, en för varje signal och med respektive utan korrektion för fading. Från dessa valdes de okorrigerade pIRIR225 åldrarna, eftersom denna signal nollställs snabbare än andra pIRIR-signaler och har en lägre fading rate än IR50. Flera av proverna hade doser som var nära mättnad eller var mättade.
Resultaten jämfördes med den tidigare beskrivna glaciationshistorien för Tatrabergen. Luminiscensåldrarna, som spänner från ca 200 till 260 ka, skulle motsvara Riss-glaciationen. Både åldrar och sedimentegenskaper motsvarar de hos andra avsättningar från norra och södra sidan av Tatrabergen och som också har korrelerats med Rissglaciationen. Tillsammans visar dessa resultat på en isframstöt till de nuvarande sluttningarna av Höga Tatra under Riss-glaciationen och att stora volymer glacifluviala sediment avsattes utanför iskanten. (Less)
Please use this url to cite or link to this publication:
author
Bejarano Arias, Ingrid LU
supervisor
organization
course
GEOR02 20192
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Luminescence dating, glacifluvial deposits, sedimentological analysis, High Tatra Mountains, IRSL dating.
publication/series
Dissertations in Geology at Lund University
report number
588
language
English
additional info
External supervisor: Juraj Janočko, Technical University of Košice, Slovakia
id
9018548
date added to LUP
2020-06-15 18:51:56
date last changed
2020-06-15 18:59:10
@misc{9018548,
  abstract     = {The Tatra Mountains have had several glaciations during the Quaternary. The deposits located in the southern foothills were classified as glacifluvial, based on geomorphology, but its sediments have not been studied in detail. Therefore, this project focused on establishing the depositional history, processes, and age of the deposits in a gravel pit, located in the Biely Váh valley in these foothills. The combination of luminescence dating with sedimentological analysis, including clast shape and maximum particle size, were the methods of choice. For the luminescence dating eleven samples were collected from the units composed mainly of sand. 
Initially optically stimulated luminescence (OSL) dating was used, but after applying the standard Single Aliquot Regeneration (SAR) protocol quality tests, it was evident that the quartz was poorly behaved with low signal intensity. The dose estimation gave bad results, even after attempting pulsed OSL and differential OSL. Therefore, it was decided to move on to feldspar grains. Given that there is a risk of fading and the fact that feldspar grains take longer to bleach, the corrective measurements were done by calculating the g-value and use of IR50 and pIRIR225 signals for the bleaching. 
The sedimentological description yielded 13 units from the lower and upper outcrops in the study area. The results of the sedimentological analysis indicated that the process of deposition had a high energy component, representative of subaerial flows. Given the features of the sediments it was identified as a hyperconcentrated flow. Moreover, for the age determination the most likely water content of the sediments was chosen, the g-values and the equivalent dose were determined, using both IR50 and pIRIR225 signals. Subsequently, four ages were obtained per sample, one for each signal, and with and without correction for fading. From these, the uncorrected pIRIR225 ages were selected, since this signal has a lower fading rate which is supported by the obtained g-values, which were smaller than 1-1.5%. 
The results were compared to the known glacial history of the Tatra Mountains. The obtained luminescence ages, which range from ca 200 to 260 ka, would correspond to the Riss glaciation. Both ages and sediment characteristics match those of the other deposits from the northern and southern Tatra foothills that also have been correlated to the Riss glaciation. Taken together, these results suggest a glacial advance to the present-day foothills of the High Tatras during the Riss glaciation and extensive deposition of glacifluvial sediments outside the ice margin.},
  author       = {Bejarano Arias, Ingrid},
  keyword      = {Luminescence dating,glacifluvial deposits,sedimentological analysis,High Tatra Mountains,IRSL dating.},
  language     = {eng},
  note         = {Student Paper},
  series       = {Dissertations in Geology at Lund University},
  title        = {Determination of depositional environment and luminescence dating of Pleistocene deposits in the Biely Váh valley, southern foothills of the Tatra Mountains, Slovakia},
  year         = {2020},
}